To add integers with different signs, subtract the lesser absolute value from the greater absolute value. Use the sign of the integer with the greater absolute value for the sum. The following steps will be useful to find the sum of two numbers with different signs.
Answer: 500m
Explanation:
If the scale of the drawing is 1:500 then the real playground should be 500:1 which is 500m
We are to form the combination of 6 objects taken 2 at a time. This can be expressed as 6C2

This means, there can be 15 different combinations of 2 members that can sit in the front row.
So, the answer to this question is option A
What you wanna do here is use a calculator, as "e" in mathematics refers to the "e" on a calculator. The tricky part about this question is that the answer for the equation is the given percentage, NOT the value for "x". From there, plug in the multiple choice answers for "x" and see which one works!
In this case, A is the correct answer. B is absurdly large, so I omitted it immediately in the attached picture.